This invention relates to a composite cylinder block and more particularly to an improved method for forming said cylinder blocks.
It is well known to form cylinder blocks for reciprocating machines such as internal combustion engines from dissimilar materials. Frequently, the cylinder block has a main body portion that is cast or otherwise formed from a lightweight material such as aluminum. However, to avoid the running of pistons of similar material (aluminum) directly on the bores of the main block, it has been the practice to use inserted liners formed from a harder material such as cast iron or the like. Various arrangements have been proposed for forming the cylinder liners and inserting them into the cylinder block. With the methods heretofore proposed, however, it has been difficult to insure the proper alignment of the cylinder liner within the cylinder block. This is particularly true with two cycle engines wherein the liner is also formed with port openings. In addition, the press fitting of the cylinder liner into the cylinder block may cause distortion at times. The previously proposed methods also have been rather expensive to make, particularly considering their other shortcomings.
It is, therefore, a principal object of this invention to provide an improved method for forming a composite cylinder block.
It is a further object of this invention to provide an improved method for making cylinder blocks for two cycle engines wherein the ports of the cylinder block and cylinder liner can be accurately and effectively aligned in a low cost method.